Patent application title: IMAGE PICKUP APPARATUS

Abstract:

An image pickup apparatus includes an optical system which forms an image
based on light from object, an image pickup device which acquires the
image of the object, a display section which displays the object, and a
focusing detection inoperative condition and a focusing detection
operative condition. The image pickup apparatus further includes an image
pickup instructing section (release button) which instructs an image of
the object to be picked up, and a control section which performs control
such that when the image pickup instructing section (release button) is
in the focusing detection operative condition, an image in the focusing
detection inoperative condition is displayed on the display section.

Claims:

1. An image pickup apparatus having a focusing detection operative
condition and a focusing detection inoperative condition, the apparatus
comprising:an optical system which forms an image based on light from
object;an image pickup device which obtains the image of the object;a
display section which displays the image of the object;a focusing
detecting section; andan image pickup instructing section which permits
the focusing detecting section to go into the focusing detection
operative condition and which instructs an image of the object to be
picked up,wherein the display section displays the image of the object
taken with the optical system in a predetermined arrangement when the
image pickup instructing section permits the focusing detection operative
condition.

2. The image pickup apparatus according to claim 1, wherein the image of
the object taken with the optical system in the predetermined arrangement
is taken with the arrangement of the optical system made before the
focusing detection operative condition.

3. The image pickup apparatus according to claim 1, wherein the image of
the object taken with the optical system in the predetermined arrangement
is taken with a first predetermined arrangement of the optical system
acquired in one focusing detection operative condition.

4. The image pickup apparatus according to claim 2, wherein the display
device further displays the image taken with the arrangement of the
optical system established for the one focusing detection operative
condition.

5. The image pickup apparatus according to claim 3, wherein the display
device further displays the image taken with the arrangement of the
optical system established for the one focusing detection operative
condition.

6. The image pickup apparatus according to claim 4, wherein the image
pickup instructing section permits a plurality of focusing detection
operative conditions, andthe display section displays the image taken
with the arrangement of the optical system established for the one
focusing detection operative condition, in a next focusing detection
operative condition.

7. The image pickup apparatus according to claim 5, wherein the image
pickup instructing section permits a plurality of focusing detection
operative conditions, andthe display section displays the image taken
with the arrangement of the optical system established for the one
focusing detection operative condition, in a next focusing detection
operative condition.

8. The image pickup apparatus according to claim 1, wherein the image
pickup device has a function of performing a plurality of reading
operations, and further has an image pickup device control section which
controls the reading operation of the image pickup device, andin the
focusing detection operative condition, pieces of luminance information
on a plurality of pixels in a vicinity of the pixels on the image pickup
device are additively mixed together and then read.

9. The image pickup apparatus according to claim 1, wherein the image
pickup device has a function of performing a plurality of reading
operations, and further has an image pickup device control section which
controls the reading operation of the image pickup device, andin the
focusing detection operative condition, luminance information on a
partial area on the image pickup device which is made up of at least one
pixel is read.

10. The image pickup apparatus according to claim 1, wherein a focusing
information acquiring section which acquires the focusing information
comprises:an image acquiring section which uses the image pickup device
to acquire a plurality of images with different blur levels formed by
light having passed through the optical system;a luminance information
acquiring section which acquires luminance information on corresponding
areas in at least two of the plurality of images;a spread parameter
calculating section which calculates a spread parameter from the
luminance information on the corresponding areas; anda control section
which relates the spread parameter to a command value sent to a drive
section which drives the optical system to a position at which an image
focusing on the object is obtained.

11. The image pickup apparatus according to claim 1, further comprising:a
recording section in which image information to be displayed on the
display section is recorded;a counter which measures the time for which
the image information recorded in the recording section is held; andan
updating section which updates the image information recorded in the
recording section.

Description:

CROSS REFERENCE TO RELATED APPLICATIONS

[0001]This is a Continuation Application of PCT Application No.
PCT/JP2006/316751, filed Aug. 25, 2006, which was published under PCT
Article 21(2) in Japanese.

[0002]This application is based upon and claims the benefit of priority
from prior Japanese Patent Application No. 2005-246095, filed Aug. 26,
2005, the entire contents of which are incorporated herein by reference.

[0006]For example, U.S. Pat. No. 4,965,840 describes a method of
arithmetically processing a plurality of images with different blur
levels to calculate a spread parameter and acquiring luminance
information at two positions with different optical path lengths for
focusing determination. Here, the spread parameter refers to a
representative value for a blur level indicated in the luminance
information, which value correlates with the variance of a point spread
function (PSF) of an optical system. Here, PSF refers to a function
representative of the spread of light beams obtained when an ideal point
image passes through an optical system.

[0007]FIG. 11 shows steps of a focusing determining method described in
U.S. Pat. No. 4,965,840. The focusing determining system acquires at
least two pieces of focusing-determining luminance information for the
same subject, the same site of the subject, and the same direction of
view by varying at least one camera parameter that has an effect on the
blur condition of a picked-up image. The camera parameter may be a focus
lens position, an aperture amount, a focal distance, or the like. In the
description of the present invention, only the focal lens position is
varied, as shown in FIG. 13.

[0008]FIGS. 12(a) and 12(b) show that a focused focal point is acquired by
driving a focus lens to vary the position of the lens and thus a blur
condition. FIG. 13 shows an example configuration of a camera system in
this case.

[0009]According to the focusing determining method, first, a first camera
parameter set and a second camera parameter set are defined (steps S101-1
and S101-2). The focus lens is then moved to a predetermined first
position (FIG. 12(a)) and to a predetermined second position (FIG. 12(b))
in order to vary the optical path length from focal surfaces FM1 and FM2
to an object D. Thus, a first piece of luminance information and a second
piece of luminance information are acquired (steps S102-1 and S102-2).

[0010]The luminance information acquired is then subjected to
normalization processes such as image scaling and luminance distribution
(steps S103-1 and S103-2). An area to be subjected to focusing
determination is selected from the luminance information acquired as
required. The selection is performed on one of the two pieces of
information (in this case, the first piece of image information) (step
S104-1). A focusing determination area for a second image acquired is
selected for the other piece of image information (second piece of image
information); the focusing determination area corresponds to the focusing
determination image processing area in the first acquired image (step
S104-2).

[0011]The first and second pieces of luminance information may contain
information on electric noise from a luminance information acquiring
section. Thus, as a preprocess for the calculation of a blur amount, an
arithmetic operation for removing noise, an arithmetic operation for
calculating the variance of PSF, and the like are performed on the
focusing determination areas selected from the first and second piece of
luminance information (steps S105-1 and S105-2). The results of the two
arithmetic operations are united together to calculate the variance of
PSF corresponding to the first or second piece of luminance information
according to this technique (step S106). A subject distance is determined
from the calculated variance of PSF on the basis of a relation between
the variance of PSF and the subject distance described in U.S. Pat. No.
4,965,840 (step S107).

[0012]Furthermore, U.S. Pat. No. 5,193,124 pre-acquires a table showing
the correspondence between a spread parameter that correlates with the
variance of PSF in an area on an image surface 2 in FIGS. 12(a) and 12(b)
and a command value sent to a focus lens driving section in order to set
the focus lens portion for focusing. The spread parameter is a value
representative of the ratio of MTF described in U.S. Pat. No. 5,193,124
or a difference in the variance of PSF between two images with different
blur levels described in U.S. Pat. No. 5,148,209. Thus, the spread
parameter for a focusing detection area is calculated, and with reference
to the above-described table, a movement command value for a driving
actuator is generated, which sets the focus lens position for focusing.

BRIEF SUMMARY OF THE INVENTION

[0013]According to a first aspect of the present invention, there is
provided an image pickup apparatus having a focusing detection operative
condition and a focusing detection inoperative condition, the apparatus
comprising:

[0014]an optical system which forms an image based on light from object;

[0015]an image pickup device which obtains the image of the object;

[0016]a display section which displays the image of the object;

[0017]a focusing detecting section; and

[0018]an image pickup instructing section which permits the focusing
detecting section to go into the focusing detection operative condition
and which instructs an image of the object to be picked up,

[0019]wherein the display section displays the image of the object taken
with the optical system in a predetermined arrangement when the image
pickup instructing section permits the focusing detection operative
condition.

[0020]According to a second aspect of the present invention, there is
provided an image pickup apparatus according to the first aspect, wherein
the image of the object taken with the optical system in the
predetermined arrangement is taken with the arrangement of the optical
system made before the focusing detection operative condition.

[0021]According to a third aspect of the present invention, there is
provided an image pickup apparatus according to the first aspect, wherein
the image of the object taken with the optical system in the
predetermined arrangement is taken with a first predetermined arrangement
of the optical system acquired in one focusing detection operative
condition.

[0022]According to a fourth aspect of the present invention, there is
provided an image pickup apparatus according to the second aspect,
wherein the display device further displays the image taken with the
arrangement of the optical system established for the one focusing
detection operative condition.

[0023]According to a fifth aspect of the present invention, there is
provided an image pickup apparatus according to the third aspect, wherein
the display device further displays the image taken with the arrangement
of the optical system established for the one focusing detection
operative condition.

[0024]According to a sixth aspect of the present invention, there is
provided an image pickup apparatus according to the fourth aspect,
wherein the image pickup instructing section permits a plurality of
focusing detection operative conditions, and

[0025]the display section displays the image taken with the arrangement of
the optical system established for the one focusing detection operative
condition, in a next focusing detection operative condition.

[0026]According to a seventh aspect of the present invention, there is
provided an image pickup apparatus according to the fifth aspect, wherein
the image pickup instructing section permits a plurality of focusing
detection operative conditions, and

[0027]the display section displays the image taken with the arrangement of
the optical system established for the one focusing detection operative
condition, in a next focusing detection operative condition.

[0028]According to an eighth aspect of the present invention, there is
provided an image pickup apparatus according to the first aspect, wherein
the image pickup device has a function of performing a plurality of
reading operations, and further has an image pickup device control
section which controls the reading operation of the image pickup device,
and

[0029]in the focusing detection operative condition, pieces of luminance
information on a plurality of pixels in a vicinity of the pixels on the
image pickup device are additively mixed together and then read.

[0030]According to a ninth aspect of the present invention, there is
provided an image pickup apparatus according to the first aspect, wherein
the image pickup device has a function of performing a plurality of
reading operations, and further has an image pickup device control
section which controls the reading operation of the image pickup device,
and

[0031]in the focusing detection operative condition, luminance information
on a partial area on the image pickup device which is made up of at least
one pixel is read.

[0032]According to a tenth aspect of the present invention, there is
provided an image pickup apparatus according to the first aspect, wherein
a focusing information acquiring section which acquires the focusing
information comprises:

[0033]an image acquiring section which uses the image pickup device to
acquire a plurality of images with different blur levels formed by light
having passed through the optical system;

[0034]a luminance information acquiring section which acquires luminance
information on corresponding areas in at least two of the plurality of
images;

[0035]a spread parameter calculating section which calculates a spread
parameter from the luminance information on the corresponding areas; and

[0036]a control section which relates the spread parameter to a command
value sent to a drive section which drives the optical system to a
position at which an image focusing on the object is obtained.

[0037]According to an eleventh aspect of the present invention, there is
provided an image pickup apparatus according to the first aspect, further
comprising:

[0038]a recording section in which image information to be displayed on
the display section is recorded;

[0039]a counter which measures the time for which the image information
recorded in the recording section is held; and

[0040]an updating section which updates the image information recorded in
the recording section.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

[0041]FIG. 1 is a diagram showing the configuration of an image pickup
apparatus in accordance with a first embodiment of the present invention;

[0042]FIG. 2 is a timing chart (1) illustrating the effects of the first
embodiment;

[0043]FIG. 3 is a timing chart (2) illustrating the effects of the first
embodiment;

[0044]FIG. 4 is a flowchart illustrating the effects of the first
embodiment;

[0045]FIG. 5 is a diagram showing the configuration of an image pickup
apparatus in accordance with a second embodiment of the present
invention;

[0047]FIG. 7 is a diagram showing an image mixed reading operation of
adding two vertical images and two horizontal images together;

[0048]FIG. 8 is a diagram showing an area 101 in the vicinity of a center
of an image pickup device 2 in which sampling is performed;

[0049]FIG. 9 is a diagram showing nine areas for sampling;

[0050]FIG. 10 is a timing chart illustrating the effects of the first
embodiment;

[0051]FIG. 11 is a diagram showing steps of a focusing determining method
described in the Background Art section;

[0052]FIG. 12 is a diagram showing that a focused focal point is acquired
by driving a focus lens to vary the position of the focus lens and thus a
blur condition; and

[0053]FIG. 13 is a diagram showing an example of the configuration of a
camera system for acquiring the focused focal point.

DETAILED DESCRIPTION OF THE INVENTION

First Embodiment

[0054]A first embodiment of the present invention will be described below
with reference to the drawings. FIG. 1 is a diagram showing the
configuration of an image pickup apparatus in accordance with the first
embodiment. The image pickup apparatus is made up of an optical system 1,
an image pickup device 2, a focused focal point arithmetic processing
section 3, an optical system control section 4, a control system storage
section 5, a driving section 6, a driving section condition detecting
section 7, a release button (image pickup instructing section) 8, an
image signal processing section (control section) 9, a display section
10, a display image recording section 11, an image recording section 12,
a focusing detecting image recording section 13, a recording section
counter 14, and an operating section counter 16.

[0055]With the above configuration, when the optical system 1 forms an
image of a subject on an image pickup device 2, the image pickup device 2
converts the image into an electric signal. The electric signal is
processed differently depending on whether the purpose is 1. to display
the image or 2. to acquire focusing information or 3. to record the
image. For example, in the case of 1., the electric signal is processed
by the image signal processing section 9, and the processed signal is
then sent to the display section 10. In the case of 2., the electric
signal is sent to the focused focal point arithmetic processing section
3. In the case of 3., the electric signal is processed by the image
signal processing section 9 and sent to the image recording section 12.
The release button 8 is used by the user to switch among 1. and 2. and 3.

[0056]Now, with reference to FIGS. 12(a) and 12(b), description will be
given of a method for acquiring focusing information, which method is
used in the present embodiment. The driving section 6 is composed of an
actuator such as a motor, a signal generating circuit that generates
signals for driving the actuator, and a mirror frame that combines the
optical system 1 with the actuator. The motor acts on the mirror frame,
combining a focus lens, the optical system 1, with the motor, to drive
the optical system 1 to control the position of the optical system 1. The
optical path length between an object D and focal surfaces (FM1 and FM2)
is adjusted to control the possible blur of an image on the image pickup
device 2. The position of the optical system 1 is controlled by measuring
the position of the mirror frame using a signal from the driving section
condition detecting section 7.

[0057]Then, the driving section 6 is used to control the optical system 1
to a predetermined first position (FIG. 12(a)) and to a predetermined
second position (FIG. 12(b)), where the first and second image pickup
devices 2, respectively, are used to take images. The taken images are
converted, by the image signal processing section 9, into digital
signals, which are then recorded in the focusing detecting image
recording section 13. The focused focal point arithmetic processing
section 3 uses the two pieces of luminance information with different
blur levels recorded in the focusing detecting image recording section 13
to calculate a value (spread parameter) correlating with the variance of
PSF. The calculating method may be the one shown in the Background Art
section or any other technique.

[0058]Now, a table stored in the control system storage section 5 will be
described. The control system storage section 5 stores spread parameters
and command values to be sent to the driving section 6 in order to set
focus lens positions required to obtain focused images corresponding to
the spread parameters; the spread parameters and the command values are
in discrete value form.

[0059]The command value to be sent to the driving section 6 in order to
set a focus lens position required to obtain a focused image is retrieved
from the table stored in the control system storage section 5, on the
basis of the spread parameter calculated from the two blurred images. The
optical system control section 4 inputs the command value to the driving
section 6. The optical system 1 is moved to a position appropriate for
focusing to enable a focused condition to be achieved.

[0060]The effects of the present embodiment will be described with
reference to FIGS. 2 to 4. FIG. 2 is a timing chart (1) illustrating the
effects of the first embodiment. FIG. 3 is a timing chart (2)
illustrating the effects of the first embodiment. FIG. 2 shows that the
non-depressed released button 8 is half-depressed to shift to a focusing
detection operative condition. FIG. 3 shows that the device is shifted to
the focusing detection operative condition with the release button 8
remaining half-depressed. FIG. 4 is a flowchart illustrating the effects
of the first embodiment.

[0061]First, the device determines whether or not the non-depressed
release button 8 (T1-1 in FIG. 2: focusing detection inoperative
condition) has been half-depressed (step S1 in FIG. 4). When the
determination is YES, the process shifts to step S6. When the
determination is NO, the device determines whether or not the release
button 8 has been fully depressed (step S1-1 in FIG. 4). When the
determination is YES, the process proceeds to step S1-2. When the
determination is NO, an image picked up by the image pickup device 2 is
displayed on the display section 10 (T2-1 in FIG. 2, step S2 in FIG. 4).
The display image recording section 11 is a frame buffer for the display
section 10. Images displayed on the display section 10 are sequentially
recorded in the display image recording section 11 (T3-1 in FIG. 2). The
recording section counter 16 manages the time for which frame buffer
images have been held so that the display image recording section 11 can
always hold the latest information. That is, if a comparison of the value
in the recording section counter 16 with a maximum value MAX1 indicates
that the value in the recording section counter 16 is greater than the
maximum value MAX1, the image in the display image recording section 11
is erased to allow the latest display image to be recorded (steps S3, S4,
and S5 in FIG. 4).

[0062]When the release button 8 is half-depressed and the determination in
step S1 is YES, focusing detection is started (T1-2 in FIG. 2: focusing
detection operative condition). The image recorded in the display image
recording section 11 in T3-1 in FIG. 2 is read (T4 in FIG. 2, step S6)
and displayed on the display section 10 (T2-2 in FIG. 2, step S7 in FIG.
4). While focusing information is being acquired, the read image is
always displayed.

[0063]Then, the configuration in FIGS. 12(a) and 12(b) are used to acquire
focusing information in accordance with a procedure shown in FIG. 11.
That is, the driving section 6 places the optical system 1 at a first
position where a first blurred image is to be obtained (T6-1 in FIG. 2).
Luminance information is then acquired and the image is recorded for
focusing detection (T5-1 in FIG. 2). The driving section 6 places the
optical system 1 at a second position where a second blurred image is to
be obtained (T6-2 in FIG. 2). Luminance information is then acquired
(T5-2 in FIG. 2). Then, these pieces of luminance information are used to
calculate a focused focal position in accordance with the procedure in
FIG. 11 (step S8 in FIG. 4). The driving section 6 places the optical
system 1 at a calculated focused focal position (T6-3 in FIG. 2, step S9
in FIG. 4). Once the optical system 1 is placed at the focused focal
position, the focusing detection is completed.

[0064]When the focusing detection is completed, a picked-up image is
displayed on the display section 10 as in the case of step S2 (T2-1 in
FIG. 2, step S2-1 in FIG. 4) and held in the display image recording
section 11 (T3-2 in FIG. 2, step S5-1 in FIG. 4). In this case, the
recording section counter 14 manages the time for which frame buffer
images have been held. The display image updating section 20 constantly
updates the information held in the display image recording section 11.
That is, if a comparison of the value in the recording section counter 14
with the maximum value MAX1 indicates that the value in the recording
section counter 14 is greater than the maximum value MAX1, the image in
the display image recording section 11 is erased to allow the latest
display image to be constantly recorded (steps S3-1, S4-1, and S5-1).

[0065]The operating section counter 16 is connected to the release button
8 and measures the time elapsed since the last start of focusing
detection. When a specified time elapses and the count value exceeds a
maximum value MAX2 (T11 in FIG. 3, step S10 in FIG. 4), focusing
detection is started again.

[0066]That is, the image recorded in the display image recording section
11 and taken in the focused condition is read (T4 in FIG. 3, step S6 in
FIG. 4) and displayed (T2-2 in FIG. 3, step S7 in FIG. 4). During the
display, a plurality of blurred images are taken to acquire focusing
information (step S8 in FIG. 4). In this case, the image taking operation
for acquiring focusing information may start at the lens position in the
focused condition or at a different position.

[0067]Then, when the release button 8 is fully depressed and the
determination in step S1-2 is YES, a focused image is taken (T10 in FIGS.
2 and 3: focusing detection inoperative condition, step S11 in FIG. 4)
and the taken image is recorded in the image recording section 12. The
above-described flow enables focusing detection to be achieved without
the need to present the user with blurred images acquired during the
acquisition of focusing information.

[0068]In the description of the present embodiment, after the focusing
detection is completed, the release button 8 remains half-depressed for a
while before the main image taking operation is started. However, the
non-depressed release button 8 may be fully depressed without being
half-depressed, to start the main image taking operation. Even when the
released release button 8 is fully depressed without being
half-depressed, if the focusing detection has not been completed, the
focusing detection is completed before the main image taking operation is
started. During the focusing detection, images are read from the display
image recording section 11 and displayed as described above.

[0069]In the description of the present embodiment, the focus lens 1 is
driven to obtain plural pieces of blur luminance information. However,
the aperture diameter may be varied to acquire luminance information at
different blur levels or a lens composed of a fluid may have its
refractive index varied to obtain luminance information for different
optical path lengths so as to allow the spread parameter to be
calculated. Furthermore, at least one of the lens position, the aperture
diameter, and the lens refractive index has only to be varied or the lens
position, the aperture diameter, and the lens refractive index may all be
simultaneously varied.

[0070]The optical system 1 is composed of a plurality of lens groups, for
example, zoom lenses, focus lenses, diaphragms, and optical filters. The
focused focal point arithmetic processing section 3 is a microprocessor
that executes arithmetic processes. A plurality of focused focal point
arithmetic processing sections 3 may be provided and may be implemented
using ASICs or FPGAs. The optical system control section 4 comprises a
driving circuit for the driving section 6 and an arithmetic processing
section that executes arithmetic processes for control. The driving
section 6 is composed of an electromagnetic motor, a piezoelectric
element, an ultrasonic driving motor, or the like. The driving section
condition detecting section 7 is a sensor that detects the speed, angular
speed, position, temperature, pressure, light quantity, or the like of
the driving section 6. The driving section condition detecting section 7
is composed of a gyro sensor, an encoder, an accelerometer, a
thermometer, a pressure gauge, a light receiving element that measures
the quantity of light, or the like.

[0071]The focused focal point arithmetic processing section executes the
method based on the arithmetic operation of the spread parameter as
described above. However, the focused focal point arithmetic processing
section may execute a method of detecting contrast.

Second Embodiment

[0072]A second embodiment of the present invention will be described
below. FIG. 5 is a diagram showing the configuration of an image pickup
apparatus in accordance with the second embodiment of the present
invention. In the second embodiment, the image pickup apparatus is
characterized by comprising an image pickup device operation control
section 15 that controls the operation of the image pickup device 2. FIG.
10 is a timing chart illustrating the effects of the second embodiment.
In FIG. 10, T12-1 denotes a display sampling mode, T12-2 denotes a
focusing detection sampling mode, and T12-3 denotes a main image taking
sampling mode. After the release button 8 is half-depressed to end the
operation of the driving section 6 at T6-1 and before luminance
information is acquired at T5-1, the image pickup device operation
control section 15 changes the sampling mode to the focusing detection
sampling mode.

[0073]The timing at which the sampling mode is changed is not particularly
limited provided that the change is made during the period from T1-2 to
T6-1, when driving of the optical system 1 is ended. However, in the
example of configuration in FIG. 5, to compensate for the timing, the
image pickup device operation control section 15 receives an end signal
from the driving section condition detecting section 7. At T5-1 and T5-2,
luminance information is obtained in the focusing detection sampling
mode. For sampling of the focusing detection condition, what is called
pixel mixed reading is performed by, for example, additively mixing two
horizontal images as shown in FIG. 6 or additively mixing two vertical
pixels and two horizontal pixels as shown in FIG. 7. This enables
sampling bands in the X and Y directions to be matched, allowing
luminance information to be obtained at a high frame rate over a wide
range. After the focusing operation is finished, the device changes to
the display sampling mode or the main image taking sampling mode.

[0074]In this case, the image data for the pixel mixed reading operation
is used only for the calculation for focusing detection. No image for
display is generated. As is the case with the configuration shown in FIG.
1, image display data may be held in the display image recording section
11 before being displayed. Then, to acquire luminance information for
focusing detection, the image information in the buffer may be presented.

Variation of the Second Embodiment

[0075]In the sampling mode suitable for acquiring luminance information
for focusing detection in accordance with the second embodiment, if the
area of an object for focusing is limited, a partial area on the image
pickup device 2 is sampled. This operation is possible when the image
pickup device 2 has a function of acquiring data on the basis of X and Y
addresses, like a MOS imager. For example, as shown in FIG. 8, only an
area 101 in the vicinity of the center of the image pickup device 2 is
sampled to provide luminance information of a high definition at a high
frame rate. In this case, since the luminance information acquired does
not reflect the image information on the entire area on the image pickup
device 2, no image for display is generated. To acquire luminance
information for focusing detection, image information in a memory is
presented.

[0076]Alternatively, a plurality of partial areas may be set and nine
areas 111 to 119 may be sampled as shown in FIG. 9. In this case, since
the luminance information acquired does not reflect the image information
over the entire area on the image pickup device, no image for display is
generated as described above.